Repeated System Preferences windows opening

We've identified a rather peculiar issue with the Zimbra preferences pane in both Snow Leopard and Lion.

Every few days, contacts and calendar stop syncing, and the user is presented with quite literally dozens of System Preferences instances, all of which display the message "System Preferences must restart in 32-bit mode" or similar. Clicking either in the affirmative or negative dismisses the window. This "32-bit mode" warning is typical when one wishes to go into the Zimbra preference pane manually.

Upon going into the Zimbra preference pane, the "traffic light" shows red, and the message in the bottom right corner shows an authentication error, despite all settings being correct. Simply re-entering either the username or password immediately resolves the problem.

It's almost as if, every few days the Zimbra connector just "forgets" either the username or password, and from that point on authentication fails. I suspect that the multiple instances of System Preferences is the connector's attempt at bringing itself to the foreground to report this authentication failure, but since it can't click OK on the 32-bit warning, it simply opens further instances of itself ad nauseam.

If it has a bearing, in every case the Zimbra server is remote, that is to say accessible via the internet connection rather than on the local LAN.

Is anyone else seeing this issue at all? We've seen it so far on 2 Snow Leopard and 2 Lion machines, all running in different locations.

Has anyone had any thoughts on this - or even confirmation that they're encountering a similar issue?

If I can't work out a solution to this one, I fear I may have to move our Mac users away from Zimbra.

Please have a look at this Wiki article - especially under "Version Considerations". So using CalDAV and CardDAV accounts in addressbook resp. iCal should solve your poblem. And as Apple has removed iSync from Lion the ZCS Connector for Apple® iSync is now obsolete, using of CalDAV/CardDAV is the solution.

Thanks for the reply mwche. Do you have a link to instructions for manual setup of CalDAV and CardDAV?

(one of the problems I've had in the past with CalDAV is getting it to work with multiple calendars: effectively I had to create a separate CalDAV "account" for each calendar. Do you know if this is still the case?)

At most you might have to modify the SSL setting or port, but I have never had to do so.

CardDAV is another issue. If you have Lion, it works reasonably well. If you have Snow Leopard, it generally won't work unless you have just a single domain without virtual domains. Do a search on the forums (and maybe wiki) for CardDAV; there are some proposed workarounds for Snow Leopard but I've never gotten any of them to work.